London Fire Brigade station manager Peter Critchell, who attended yesterday's fire, said: “At the height of the incident the flames were coming through the roof and there was thick billowing grey smoke.

“We had well over 100 firefighters at the scene and used water jets to attack the fire from all four corners of the building, which was fully alight.

“We evacuated 30 people and firefighters managed to salvage around 500 artefacts from the museum."

Fire engines were still at the scene this morning, damping down the remaining pockets of fire. The cause of the blaze is under investigation.